There was a phone call interview and then two on-site interviews. Both interviewers were very friendly and not at all intimidating. They sent an e-mail of how to prepare for the interview which was more intense than the interview itself.

I had a phone interview, and an on-sight final round with 2 back-to-back. The initial interview was with the co-founder, and was purely behavioral. The second interview was a little more technical, but they weren't too difficult; as a college freshman you're not expected to know much.